Cover a 9x9 in. pan with foil and spray with cooking oil spray.
In a heavy sauce pan add sugar,coccoa,salt, and milk. Stir over medium heat until it begins to boil. Boil without stiring until soft ball stage-approx. 240 degrees on a candy themo. or approx. 15-20 min.
Remove from heat. Add the vanilla and peanut butter. Stir until well blended. Pour into pan. Cut when cool.